State Route 45 is a north–south state highway in the northeastern portion of the U.S. state of Ohio. Its southern terminus is at the State Route 7/State Route 39 concurrency in Wellsville, and its northern terminus is at State Route 531 about three miles (4.8 km) west of Ashtabula.

State Route 39 is a primarily east–west running state highway in north-central and northeastern portion of the U.S. state of Ohio. The route runs through seven counties on its approximately 155-mile (249 km) trip through the region. Its western terminus is at State Route 103 near New Washington, and its eastern terminus is at PA 68 near East Liverpool.